Nanostructured surfaces

Comparison of adsorption properties of high-carbon fly ash precursor, zeolite-carbon composite and pure zeolite relative to heavy metal ions
Wiśniewska M.1, Medykowska M.1, Szewczuk-Karpisz K.2, Panek R.3
1Department of Radiochemistry and Environmental Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University in Lublin, M. Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland,
E-mail: wisniewska@hektor.umcs.lublin.pl;
2Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland;
3Lublin University of Technology, Nadbystrzycka 40, 20-618, Lublin, Poland.
Considering the growing needs of environmental remediation, new effective solutions should be sought. Therefore, the adsorbed amounts of heavy metal ions, such as lead(II) and zinc(II), on the surface of high-carbon fly ash precursor (HiC FA), synthesized zeolite-carbon composite (Na-P1(C)) and pure zeolite (Na-P1) were investigated. The applied solids were characterized using: X-ray Diffraction analyzer (XRD), Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy analyzer (SEM-EDS), Nitrogen Adsorption/Desorption method and Particle Size analysis. The heavy metal concentration in the probes was determined applying Inductively Coupled Plasma Optical Emission spectroscopy (ICP-OES). Electrokinetic study included measurements of electrophoretic mobility as well as solid surface charge density of the solid particles, without and with adsorbed heavy metals. Adsorption/desorption and electrokinetic measurements were performed in the systems containing one or two adsorbates. The obtained results indicated that Pb(II) ions were adsorbed more efficiently than Zn(II) ones and their adsorption occurs fast. The largest adsorption takes place on Na-P1 surface (407.34 mg/g for Pb(II)), whereas - the smallest on HiC FA one (78.67 mg/g for Pb(II)). Bounding of all adsorbates occurs trough chemisorption and ion adsorption follow the Langmuir model. In mixed systems of adsorbates, Pb(II) ions adsorb more efficiently due to the molecular sieving effect. The presence of Zn(II) ions influences minimally the adsorbed amount of Pb(II) ones. Contrary, the addition of Pb(II) ions to the system resulted in threefold decrease in the adsorbed amount of Zn(II) ions.
Funding: This work was ﬁnanced by the National Centre for Research and Development project Lider contract number LIDER/19/0072/L-9/17/NCBR/2018.